JP2017226857A - Surface treatment organic pigment for color filter, manufacturing method and color filter thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment organic pigment excellent in chroma saturation of colored article, and low in hue change and small in heat resistance of the colored article even with receiving heat history over long time.SOLUTION: There are provided a surface treatment organic pigment containing a copolymer (B) nonvolatile content of 2 or more kind of (meth)acrylic acid esters having different carbon atoms in side chains of 0.1 to 15 part per 100 part of an organic pigment (A) in terms of mass, a manufacturing method of the above described surface treatment organic pigment including compression heating the organic pigment (A) in a presence of the copolymer (B) nonvolatile content of 2 or more kind of (meth)acrylic acid esters having different carbon atoms in side chains in a liquid medium or solvent salt milling the organic pigment (A) in the presence of the copolymer (B) nonvolatile content of 2 or more kind of (meth)acrylic acid esters having different carbon atoms in side chains, and a color filter containing the surface treatment organic pigment described above or the surface treatment organic pigment obtained by the manufacturing method described above in a pixel portion.SELECTED DRAWING: None

Description

  The present invention relates to a surface-treated organic pigment for a color filter, a method for producing the same, and a color filter.

  When dispersing an organic pigment in a medium that needs to be colored, in order to be able to disperse more easily or to increase the stability in the medium after the dispersion, the organic pigment by a surfactant or an organic pigment derivative is used. Surface treatment is often performed. By this surface treatment, the dispersibility and dispersion stability of the organic pigment that has not been subjected to any surface treatment can be improved.

  When the medium that needs to be dispersed is a synthetic resin, a synthetic resin is often used for this surface treatment. Specifically, a method of solvent salt milling of an organic pigment in the presence of an acrylic resin non-volatile component is known.

  The surface treatment of organic pigments with synthetic resins has been studied according to general polymer categories such as (meth) acrylic resins, epoxy resins, polyester resins, polyurethane resins, etc. Systematically examine whether the polymers of the above are highly effective in improving dispersibility and dispersion stability, and what type of polymer is selectively the most effective in the same category of polymers. However, there are many unclear points.

  By the way, organic pigments used for high-performance applications such as inkjet inks and color resists for color filters require higher-definition printing than general-purpose organic pigments used for coloring paints and thermoplastic plastic moldings. Therefore, a finer organic pigment is demanded.

  However, since fine organic pigments are more likely to aggregate than general-purpose organic pigments, the surface treatment of organic pigments used in general-purpose applications does not necessarily require surface treatment using any synthetic resin. However, the improvement effect as expected is not obtained, and the actual condition is that the synthetic resin having the optimum structure in the optimum category is selected by trial and error.

  Specifically, for example, as a surface treatment method of an organic pigment used for preparing a color resist for a color filter, a solvent salt milling method of an organic pigment in the presence of a (meth) acrylic resin nonvolatile component (Patent Document 1), A method of heating an organic pigment under pressure in the presence of a polyurethane resin in a liquid medium is known (Patent Document 2).

JP-A-8-179111 WO 10/061830

  However, the saturation of the colored material obtained from the organic pigment surface-treated by the above-described conventional manufacturing method is still insufficient, and the hue of the colored material changes greatly when subjected to a heat history for a long time. In fact, the heat resistance was poor.

  In order to solve the above problems, the present inventors have intensively studied the surface treatment effect of organic pigments using various synthetic resins. When a surface treatment is carried out with a copolymer of the above, a colored product in which the above-mentioned drawbacks are eliminated can be obtained. In the present invention, the present invention has been completed by finding that it is a color filter capable of liquid crystal display excellent in heat resistance of luminance.

That is, the present invention relates to a copolymer of two or more (meth) acrylic acid esters (B) having a non-volatile content of 0.1 to 15 parts in terms of mass per 100 parts of the organic pigment (A) and having different side chain carbon atoms. Provided is a surface-treated organic pigment for a color filter.
In the present invention, whether the organic pigment (A) is heated under pressure in the presence of a non-volatile copolymer (B) of two or more types of (meth) acrylic acid esters having different side chain carbon atoms in the liquid medium. Or (meth) acrylic acid ester two or more types of copolymers (B) having different side chain carbon atoms (B) surface-treating organic pigments for color filters that perform solvent salt milling of organic pigments (A) in the presence of non-volatile content A manufacturing method is provided.
Further, the present invention provides a color filter comprising any one of the above-described surface-treated organic pigments in a pixel portion.

Since the surface-treated organic pigment of the present invention contains the organic pigment (A) and the specific copolymer (B) at a predetermined ratio, even if the thermal history is received over a long period of time, the hue of the colored material changes. There is a particularly remarkable technical effect that a small colored product having excellent coloring heat resistance can be obtained.
Moreover, the method for producing a surface-treated organic pigment of the present invention has a particularly remarkable technical effect that the above-described surface-treated organic pigment can be easily obtained.
Furthermore, since the color filter of the present invention contains the above-described surface-treated organic pigment or the surface-treated organic pigment obtained by the above-described manufacturing method in the pixel portion, a liquid crystal display excellent in heat resistance of luminance is possible. There is a remarkable technical effect.

  The surface-treated organic pigment of the present invention is a copolymer of two or more (meth) acrylic acid esters having different number of carbon atoms in the side chain per 100 parts of the organic pigment (A) in terms of mass (B) nonvolatile content of 0.1. It contains ˜15 parts.

  Examples of the organic pigment (A) include known and conventional ones such as phthalocyanine pigments, quinacridone pigments, azo pigments, dioxazine pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, and organometallic complex pigments.

  The organic pigment (A) in the present invention may have any particle size, but the colorant can be a clearer colored product when the average particle size of the primary particles is 100 nm or less in the dry powder. It is preferable because it is easy to obtain. On the other hand, since the organic pigment (A) having a smaller particle diameter generally has lower heat resistance, it is necessary to improve the heat resistance by some means without impairing the sharpness.

  In the present invention, the average particle diameter of primary particles is measured as follows. First, the particle | grains in a visual field are image | photographed with a transmission electron microscope or a scanning electron microscope. And the longest length (maximum length) of the internal diameter of each particle | grain is calculated | required about 50 of the primary particles which comprise the aggregate on a two-dimensional image. The average value of the maximum length of each particle is defined as the average particle size of the primary particles.

  Also, copolymers of two or more (meth) acrylic acid esters having different numbers of carbon atoms in the side chain (B

As for), any known and commonly used ones can be used. A (meth) acrylic acid ester is a compound containing an ester bond formed from (meth) acrylic acid and other various alcohols, and a carbon atom chain at the end of the ester bond COO derived from the alcohol. That contains. Typically, those in which the carbon chain is an alkyl group are referred to as (meth) acrylic acid alkyl esters. In the case of (meth) acrylic acid alkyl ester, the side chain means an alkyl group. In this industry, not only (meth) acrylic acid alkyl esters but also compounds having a carbon chain other than an alkyl group are well known. Therefore, in the present invention, not only (meth) acrylic acid alkyl esters but also carbon chains. However, including a compound other than an alkyl group, it shall be referred to as a (meth) acrylic acid ester.

  Examples of such (meth) acrylic acid esters include (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and iso-propyl (meth). Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate [lauryl (meth) Acrylate], octadecyl (meth) acrylate [stearyl (meth) acrylate] and other (meth) acrylic acid alkyl esters having an alkyl group; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl Meth) acrylate, containing an alicyclic group such as dicyclopentanyl (meth) acrylate (meth) acrylic acid ester;

Methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol # 400 (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, ethyl carbitol (meta ) Acrylate, 2-ethylhexyl carbitol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, p-nonylphenoxyethyl (meth) acrylate, p-nonylphenoxypolyethylene (Meth) acrylic acid ester containing ether group such as glycol (meth) acrylate; (Meth) containing an aromatic ring acrylate (meth) acrylic acid ester;
And so on.

  In the present invention, the copolymer (B) of two or more (meth) acrylic acid esters having different numbers of carbon atoms in the side chain refers to carbon atoms in the side chain among various (meth) acrylic acid esters as described above. It means a polymer obtained by selecting two or more types having different numbers and combining them for copolymerization.

  As the copolymer (B), the glass transition temperature (Tg) as high as possible is excellent in its own heat resistance, but when used in combination with the organic pigment (A), it has excellent heat resistance due to interaction. The copolymer which is Tg0-150 degreeC is more preferable at the point which can be exhibited.

  As the copolymer (B), any molecular weight can be used. Specifically, the copolymer having a weight average molecular weight of 5,000 to 100,000 has an affinity for the organic pigment (A). It is preferable because of its large properties and greater effect of improving heat resistance.

  The copolymer (B) can be synthesized by various conventionally known reaction methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In this case, known and commonly used polymerization initiators, surfactants and antifoaming agents can be used in combination.

  The copolymer (B) is composed of two or more (meth) acrylic acid esters having different side chain carbon atoms as described above as essential monomers, and other comonomer copolymerizable therewith. It may be copolymerized.

  Examples of such comonomers include vinyl esters such as vinyl acetate, vinyl propionate and tertiary vinyl carboxylate; heterocyclic vinyl compounds such as vinylpyrrolidone; vinyl chloride, vinylidene chloride, vinylidene fluoride, and the like. Halogenated olefins, cyano group-containing monomers such as acrylonitrile and methacrylonitrile; vinyl ethers such as ethyl vinyl ether and isobutyl vinyl ether; vinyl ketones such as methyl vinyl ketone; α-olefins such as ethylene and propylene; butadiene, Examples include dienes such as isoprene; styrene monomers such as styrene, vinyl toluene, α-methyl styrene, dimethyl styrene, tert-butyl styrene, and chlorostyrene.

  According to the present inventors, the copolymer (B) is derived from two or more (meth) acrylic acid esters and contains not only side chains with different numbers of carbon atoms but also epoxy groups. It has been found that this is more excellent in heat resistance than a copolymer containing only side chains with different numbers of carbon atoms, because the hue is less likely to change even when subjected to a thermal history.

  The method for introducing the epoxy group into the copolymer is not particularly limited, and even if a radical polymerizable monomer containing an epoxy group is polymerized as an essential component, the copolymer synthesized earlier is later added. Although it may be modified with an epoxy group, since it is easy to introduce, a monomer containing two or more (meth) acrylic acid esters having different number of carbon atoms in the side chain and a monomer containing an epoxy group is polymerized as an essential component. Is preferred.

  Examples of the monomer having an epoxy group include epoxy group-containing monomers such as glycidyl (meth) acrylate, allyl glycidyl ether, and 4-hydroxybutyl (meth) acrylate glycidyl ether.

  The copolymer (B) is preferably a copolymer obtained by polymerizing, as essential components, two or more (meth) acrylic acid esters having different side chain carbon atoms and an epoxy group-containing monomer. Yes, when the total monomer constituting the copolymer (B) is 100% in terms of mass, the copolymer having the epoxy group-containing monomer is 3 to 35% by mass of the total monomer Compared to copolymers of only two or more (meth) acrylic acid esters having different number of carbon atoms in the side chain, higher heat resistance can be obtained and dispersibility in a medium to be colored is also required. It is preferable because it becomes good.

In a copolymer in which the monomer having an epoxy group is 3 to 35% by mass of the total monomer, the greater the amount of the monomer having an epoxy group, the greater the saturation or The change in chromaticity tends to be small.
The epoxy group in the copolymer (B) may be a functional group in which part or all of the epoxy group reacts with a nucleophile to open a ring. For example, when the copolymer (B) is obtained by reacting all of the epoxy groups in the copolymer with hydrochloric acid to form an α-chlorohydrin group, the copolymer containing the original epoxy group is used. Has the same effect of improving heat resistance as it was.

  The surface-treated organic pigment of the present invention has a non-volatile content of two or more kinds of copolymers (B) of two or more (meth) acrylic acid esters having different side chain carbon atoms per 100 parts of the organic pigment (A) in terms of mass. It is sufficient if it is contained so as to be 1 to 15 parts, and among them, the copolymer (B) is contained when it is 0.5 to 12 parts, particularly 1 to 10 parts per 100 parts of the organic pigment (A). In view of this, it is possible to obtain a surface-treated organic pigment having the most balanced technical effects, other technical effects such as dispersibility in a medium to be colored and dispersion stability, and economic efficiency.

  Such a surface-treated organic pigment of the present invention can be prepared by mixing the organic pigment (A) and the copolymer (B) by any means. As a simple preparation method, for example, a method of mixing the organic pigment (B) and the copolymer (B) non-volatile content, and mixing and stirring the organic pigment (A) in the liquid medium solution of the copolymer (B) Then, there is a method of filtering and drying.

  However, the present inventors are able to expect a stronger interaction between the organic pigment (A) and the copolymer (B) than the simple preparation method described above, specifically, in the liquid medium, Copolymers of two or more (meth) acrylic acid esters having different chain carbon atoms (B) The organic pigment (A) is heated under pressure in the presence of nonvolatile components, or the number of carbon atoms in the side chain is different. (Meth) acrylic acid ester two or more types of copolymers (B) The surface-treated organic pigment prepared by solvent salt milling of the organic pigment (A) in the presence of non-volatile content is the simpler method described above It has been found for the first time that a greater effect of improving heat resistance is achieved compared to the surface-treated organic pigment prepared in (1). Hereinafter, the former preparation method is referred to as a pressure heating method, and the latter preparation method is referred to as a solvent salt milling method.

  In the method for producing the two surface-treated organic pigments of the present invention, as the organic pigment (A), for example, I. Pigment Blue 15: 6 (ε-type copper phthalocyanine pigment), C.I. I. Pigment Green 36 (copper halide phthalocyanine pigment) and C.I. I. It is a particularly excellent production method for obtaining a surface-treated organic pigment containing a phthalocyanine pigment such as CI Pigment Green 58 (a zinc halide phthalocyanine pigment).

  First, the pressure heating method will be described. According to the pressure heating method, for example, the organic pigment (A) and a solution or dispersion in which the copolymer (B) is dissolved or dispersed in a liquid medium are mixed and stirred and heated. The surface of the organic pigment (A) can be more uniformly and reliably coated with the copolymer (B) than when the coating is not performed. Further, by applying pressure and heating, the surface of the organic pigment (A) particles in the case of simple heating is not only coated with the copolymer (B) but also voids such as pores of the organic pigment (A) particles. The penetration of the copolymer (B) into the portion can be promoted, and the effect of coating is further enhanced.

  At this time, when a liquid medium (referred to as an aqueous medium) containing only water or water as a main component and containing a water-soluble organic solvent is used as the liquid medium, the mixture heating is performed using only the organic solvent as the liquid medium. Compared to the organic pigment (A) itself, the change in crystal shape and the like is small, and the hue change is small, which is preferable.

  Examples of the water-soluble organic solvent include propylene glycol monomethyl ether acetate, ethyl alcohol, isopropyl alcohol, and isobutyl alcohol.

  The aqueous medium used for the pressure heating is preferably in a large excess with respect to the organic pigment (A), and the pressure heating results in 15 to 100 parts per part of the organic pigment (A) in terms of mass. The amount of the charged copolymer (B) involved in the coating of the organic pigment (A) is further increased, and the outflow of the copolymer (B) in the filtration step described later is reduced. Also, it is more preferable to shorten the process time itself.

  When a surface-treated organic pigment is prepared from the organic pigment (A) and the copolymer (B) by a pressure heating method, the finally obtained surface-treated organic pigment is an organic pigment (A) 100 in terms of mass. Although both are prepared so that it may become 0.5-12 parts of copolymer (B) per part, since the interaction including adsorption | suction between an organic pigment (A) and a copolymer (B) is strong. The non-volatile content of the charged copolymer (B) does not flow out, and at least 70% of the non-volatile content in terms of mass remains in the organic pigment (A).

  Heating of the organic pigment (A) and the copolymer (B) can be performed in a sealed system in a range of 30 minutes to 5 hours under stirring at a temperature of 100 to 150 ° C. after mixing them. it can. By heating in a closed system in this way, a pressurized state is formed, and as described above, the copolymer (B) penetrates into the voids of the pigment particles, so that only the particle surface is covered. Compared with, a more excellent effect is exhibited.

  Next, the solvent salt milling method will be described. According to the solvent salt milling method, for example, the organic pigment (A) and the copolymer (B) are kneaded by applying mechanical stress with a water-soluble inorganic salt and a hydrophilic organic solvent, thereby forming the organic pigment (A). The particle diameter of the organic pigment (A) can be uniformly and reliably coated on the surface of the organic pigment (A) after the particle diameter is made fine and the particle shape is substantially cubic.

  Specifically, in this solvent salt milling, an organic pigment, a water-soluble inorganic salt, and a hydrophilic organic solvent that does not dissolve the organic pigment are charged into a kneader, and kneading and grinding are performed therein. In the kneading, when the conversion of the crystal form of the raw material is not intended, a commercially available ε-type copper phthalocyanine pigment can be used as the raw material for the kneading as the organic pigment (A). On the other hand, when the conversion of the crystal form is intended, a crude organic pigment having a crystal form different from that after kneading can be used as the raw material for kneading as the organic pigment (A). Specifically, the ε-type copper phthalocyanine pigment can also be obtained by kneading as described above using a crude α-type copper phthalocyanine pigment as a raw material.

  When the surface-treated organic pigment is prepared from the organic pigment (A) and the copolymer (B) by the solvent salt milling method, the finally obtained surface-treated organic pigment is co-polymerized per 100 parts of the organic pigment (A). Although both are charged so that it may become 0.5-12 parts of a polymer (B), since an interaction including adsorption | suction between an organic pigment (A) and a copolymer (B) is strong, it is pressurization. Similar to the heating method, the charged copolymer (B) non-volatile component hardly flows out, and at least 70% of the non-volatile component in terms of mass remains in the organic pigment (A).

  As the water-soluble inorganic salt, for example, inorganic salts such as sodium chloride, potassium chloride, sodium sulfate and the like are preferably used. Moreover, it is more preferable to use an inorganic salt having an average particle size of 0.5 to 50 μm. Such an inorganic salt can be easily obtained by pulverizing a normal inorganic salt.

  Moreover, it is preferable to set it as 8-20 parts with respect to 1 part of organic pigments (A) by mass conversion, and, as for the usage-amount of the said inorganic salt, it is more preferable to set it as 10-15 parts.

  As the water-soluble organic solvent, those capable of suppressing crystal growth can be suitably used. For example, diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2- (methoxymethoxy) ethanol, 2-butoxy Ethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, 1,2-pro Or the like can be used Njioru but ethylene glycol or diethylene glycol are preferred.

  Although the usage-amount of the said water-soluble organic solvent is not specifically limited, 0.01-5 parts is preferable with respect to 1 part of organic pigments (A) in conversion of mass.

  It is preferable to perform kneading | mixing temperature between 60-150 degreeC. When the organic pigment (A) is a copper phthalocyanine pigment, if the temperature is between 80 ° C. and 120 ° C., the ε conversion rate of ε-type copper phthalocyanine (ε-type crystallization rate contained in copper phthalocyanine) may be increased. The surface treated organic pigment thus obtained is preferable for a color filter because it can reduce the decrease in heat resistance, contrast and the like described later.

  As an apparatus used for this kneading, there is a kneader, a mix muller, Trimix (trade name) manufactured by Inoue Seisakusho, which is a planetary mixer described in JP-A-2007-100008, and JP-A-4-122778. The continuous twin-screw extruder described above, Miracle KCK manufactured by Asada Tekko Co., Ltd., which is a continuous single-screw kneader described in JP-A-2006-306996, and the like can be used.

  When a phthalocyanine pigment is used as the organic pigment (A), a pressure heating method or a solvent salt milling method can be adopted as a method for preparing the surface-treated organic pigment. As the organic pigment (A), a metal phthalocyanine is used. When obtaining a surface-treated organic pigment containing a pigment, it is preferable to employ a solvent salt milling method.When obtaining a surface-treated organic pigment containing a halogenated metal phthalocyanine pigment as the organic pigment (A), It is preferable to employ a pressure heating method.

  In both the pressure heating method and the solvent salt milling method, the mixture that has been heated or kneaded in the liquid medium is cooled, for example, and the liquid medium is removed therefrom, and the solid is washed and filtered as necessary. The powder of the surface-treated organic pigment of the present invention containing the organic pigment (A) and the copolymer (B) non-volatile content can be obtained by drying, pulverizing and the like.

  As washing, either water washing or hot water washing can be employed. The number of washings can be repeated in the range of 1 to 5 times. By washing, the copolymer (B) not adsorbed on the organic pigment (A) can be easily removed. If necessary, acid cleaning, alkali cleaning, and solvent cleaning may be performed so as not to change the crystal state. The amount of non-volatile content of copolymer (B), which is an active ingredient, contained in the surface-treated organic pigment (so-called yield) can be determined, for example, from the amount of copolymer extracted by solvent extraction of the surface-treated organic pigment, It can obtain | require from the outflow amount in the filtrate with respect to a polymer (B).

  Examples of the drying after filtration and washing described above include batch-type or continuous drying in which the pigment is dehydrated and / or desolvated by heating at 80 to 120 ° C. with a heating source installed in a dryer. Examples of the dryer generally include a box dryer, a band dryer, and a spray dryer. In particular, spray dry drying is preferable because it is easily dispersed during paste preparation. In addition, the pulverization after drying is not an operation for increasing the specific surface area or reducing the average particle diameter of the primary particles, but for example, the pigment is a lamp as in the case of drying using a box dryer or a band dryer. This is carried out in order to break up the pigment into a powder when it becomes a lump, such as a mortar, a hammer mill, a disk mill, a pin mill, a jet mill or the like. Thus, a dry powder containing a surface-treated organic pigment containing the organic pigment (A) and the copolymer (B) as a main component is obtained.

  The surface-treated organic pigment of the present invention may contain impurities such as a free metal and a free metal ion source. However, in the case where it is used for coloring a pixel portion of a color filter, the impurities described above are as much as possible. Less is preferable. For example, when the organic pigment (A) is a phthalocyanine pigment, the surface-treated organic pigment has an adverse effect on the liquid crystal display characteristics when the content of the metal ion source such as copper, zinc, copper ion, or zinc ion is as small as possible. It is preferable because it becomes difficult. The contained free metal may be a free metal remaining when the metal phthalocyanine is synthesized or may be generated by decomposition of the metal phthalocyanine after synthesis.

  Such a free metal and free metal ion source can be washed with acids as described in JP-A-2008-308605. Examples of the acids used include hydrochloric acid and sulfuric acid, and the concentration of hydrochloric acid and sulfuric acid is preferably 0.5% to 4%. Moreover, the temperature at the time of washing | cleaning has preferable 50-90 degreeC. Moreover, you may wash | clean using water.

  In the case of the surface-treated organic pigment of the present invention containing a metal phthalocyanine pigment as the organic pigment (A), the free metal content is 900 ppm in the surface-treated organic pigment in terms of mass in that the heat resistance of the color filter is small. The following is preferable.

  The surface-treated organic pigment in the present invention has high dispersibility and dispersion stability in a liquid medium, the viscosity of the pigment dispersion described later is low, and the Newton fluidity remains high because it is dispersed in fine particles. For example, when a color filter pixel portion is manufactured from now, a color filter having a high luminance, contrast, and high light transmittance can be obtained by forming a uniform coating film.

  The surface-treated organic pigment of the present invention thus obtained has a clear and excellent chroma when the colored medium is colored, and the hue of the colored material does not change greatly even when subjected to heat history over a long period of time. Excellent heat resistance. Therefore, it is suitable not only for coloring the pixel portion of the color filter but also for coloring paint, plastic, printing ink, rubber, leather, textile printing, electrophotographic toner, inkjet ink, thermal transfer ink, and the like.

  When the surface-treated organic pigment of the present invention is used to form a pixel portion of a color filter, the surface-treated organic pigment of the present invention containing a metal phthalocyanine pigment as the organic pigment (A) may contain dioxazine as necessary. A pigment can be further contained. The surface-treated organic pigment of the present invention containing a diketopyrrolopyrrole pigment as the organic pigment (A) can contain an anthraquine pigment as necessary. If necessary, the surface-treated organic pigment of the present invention containing a halogenated metal phthalocyanine pigment as the organic pigment (A) can contain a quinophthalone pigment or an organometallic complex pigment.

  Furthermore, the surface-treated organic pigment of the present invention includes a sulfonic acid derivative, an N- (dialkylamino) methyl derivative, an N- (dialkylaminoalkyl) sulfonic acid amide derivative, and a phthalimide alkyl derivative of the organic pigment (A). Such as organic pigment derivatives, Dispavik 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170, Dispersic 171, Dispersic 174, Dispersic 180, Dispersic 182 and Dispersic 183 , Dispersic 184, Dispersic 185, Dispersic 2000, Dispersic 2001, Dispersic 2020, Dispersic 2050, Dispersic 2070, Dispers FP2096, Disperbic 2150, Disperbic LPN21116, Disperbic LPN6919, Fuka 46, Fuka 47, Fuka 452, Fuka LP4008, Fuka 4009, Fuka LP4010, Fuka LP4050, Fuka LP4055, Fuka 401, Fuka 401, Fuka 401, Fuka 401, Fuka 401 402, EFKA 403, EFKA 450, EFKA 451, EFKA 453, EFKA 4540, EFKA 4550, EFKA LP4560, EFKA120, EFKA150, EFKA1501, EFKA1502, EFKA1503, Lubrizol Solsperse 3000, Solsperse 9000, Solsperse 13240 Solsparse 13650, Solsparse 13940, Solsparse 17000, Solsparse 18000, Sols 20000, Sol Sparse 21000, Sol Sparse 20000, Sol Sparse 24000, Sol Sparse 26000, Sol Sparse 27000, Sol Sparse 28000, Sol Sparse 32000, Sol Sparse 36000, Sol Sparse 37000, Sol Sparse 38000, Sol Sparse 41000, Sol Sparse 42000, Sol Sparse 43000, Sol Sparse 46000, Sol Sparse 54000, Sol Sparse 54000 71000, Ajinomoto Co., Inc. Ajisper PB711, Ajisper PB821, Ajisper PB822, Ajisper PB814, Ajisper PN411, Ajisper PA111, dispersants such as acrylic resin, urethane resin, alkyd resin, wood rosin, gum rosin, tall rosin, etc. Natural rosin, Modified rosins such as polymerized rosin, disproportionated rosin, hydrogenated rosin, oxidized rosin, maleated rosin, rosinamine, lime rosin, rosin alkylene oxide adduct, rosin alkyd adduct, rosin derivatives such as rosin modified phenol, etc. at room temperature A liquid and water-insoluble synthetic resin can be contained. Addition of these dispersants and resins also contributes to reduction of flocculation, improvement of pigment dispersion stability, and improvement of viscosity characteristics of the dispersion.

  The surface-treated organic pigment of the present invention can be used for any known and commonly used application. However, when it is contained in the pixel portion of a color filter, it has an average primary particle diameter of 0.01 to 0.10 μm. If it exists, pigment aggregation is also comparatively weak and the dispersibility to the synthetic resin etc. which should be colored becomes more favorable.

  By incorporating the surface-treated organic pigment of the present invention described above or the surface-treated organic pigment obtained by the production method of the present invention into the pixel portion of each color of R, G, B of the color filter, a color filter can be obtained. I can do it. Specifically, for example, C.I. I. From the surface-treated organic pigment of the present invention containing a diketopyrrolopyrrole pigment such as C.I. I. From the surface-treated organic pigment of the present invention containing a halogenated metal phthalocyanine pigment such as C.I. I. B pixels can be obtained from the surface-treated organic pigment of the present invention containing a metal phthalocyanine pigment such as CI Pigment Blue 15: 6.

  As described above, the surface-treated organic pigment of the present invention can be used for forming a pattern of each color pixel portion of the color filter by a known method. Typically, a photosensitive composition for a color filter pixel portion containing the surface-treated organic pigment for a color filter of the present invention and a photosensitive resin as essential components can be obtained.

  As a method for producing a color filter, for example, after the surface-treated organic pigment of the present invention is dispersed in a dispersion medium made of a photosensitive resin, a glass or the like is formed by a slit coating method, a spin coating method, a roll coating method, an inkjet method, There is a method called photolithography in which a coating is applied on a transparent substrate, and then this coating film is subjected to pattern exposure with ultraviolet rays through a photomask, and then the unexposed portions are washed with a solvent or the like to obtain each color pattern. Can be mentioned.

  In addition, a color filter may be manufactured by forming a pattern of each color pixel portion by an electrodeposition method, a transfer method, a micellar electrolysis method, or a PVED (Photovoltaic Electrodeposition) method. The surface-treated organic pigment of the present invention is extremely useful in, for example, a method for producing a color filter in which baking is included in the process because the hue change is small even when subjected to a thermal history.

  To prepare a photosensitive composition for a color filter pixel portion, for example, the surface-treated organic pigment of the present invention, a photosensitive resin, a photopolymerization initiator, and an organic solvent that dissolves the resin are mixed as essential components. To do. The production method is generally a method in which a dispersion is prepared using the surface-treated organic pigment of the present invention, an organic solvent, and a dispersant as required, and then a photosensitive resin is added thereto. is there.

  Dispersants used as necessary include, for example, Big Chemie Dispersic (DisperbyK registered trademark) 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170, Efka 46, Efka 47, and the like. It is done. In addition, a leveling agent, a coupling agent, a cationic surfactant, and the like can be used together.

  Examples of the organic solvent include aromatic solvents such as toluene, xylene, and methoxybenzene, acetate solvents such as ethyl acetate and butyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and ethoxyethyl propionate. Propionate solvents such as alcohol solvents such as methanol and ethanol, ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether and diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and fats such as hexane Group hydrocarbon solvents, N, N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, ani Emissions, nitrogen compound-based solvent such as pyridine, a lactone-based solvents such as γ- butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate, there is water. As the organic solvent, polar solvents such as propionate-based, alcohol-based, ether-based, ketone-based, nitrogen compound-based, lactone-based, water and the like that are water-soluble are particularly suitable.

  Per 100 parts by mass of the surface-treated organic pigment of the present invention, 300 to 1000 parts by mass of an organic solvent, and optionally 0 to 100 parts by mass of a dispersant and / or 0 to 20 parts by mass of a phthalocyanine derivative, The dispersion can be obtained by stirring and dispersing as described above. Next, 3 to 20 parts by weight of the photosensitive resin per 1 part by weight of the surface-treated organic pigment of the present invention, 0.05 to 3 parts by weight of a photopolymerization initiator per 1 part by weight of the photosensitive resin, and the dispersion are necessary. In accordance with the above, an organic solvent is further added, and the mixture is stirred and dispersed to be uniform, whereby a photosensitive composition for a color filter pixel portion can be obtained.

  Examples of photosensitive resins that can be used in this case include urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like, Bifunctional monomers such as 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis (acryloxyethoxy) bisphenol A, 3-methylpentanediol diacrylate, Trimethylol propaton triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate It includes photopolymerizable monomers such as polyfunctional monomers such as.

  Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethyl ketal, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis (4′-azidobenzal) -2-propane, 1,3-bis (4′- Azidobenzal) -2-propane-2′-sulfonic acid, 4,4′-diazidostilbene-2,2′-disulfonic acid, and the like.

  The thus-prepared photosensitive composition for a color filter pixel portion can be converted into a color filter by performing pattern exposure with ultraviolet rays through a photomask and then washing the unexposed portion with an organic solvent or alkaline water. it can.

  Hereinafter, the present invention will be specifically described using synthesis examples, comparative synthesis examples, examples, and comparative examples. In these examples, “%” means mass percent.

(Synthesis Example 1)
A four-necked flask equipped with a stirrer, a thermometer, a condenser tube and a nitrogen inlet tube was charged with 1540 parts of propylene glycol monomethyl ether acetate, heated to 110 ° C. under a nitrogen stream, and then 623 parts of methyl methacrylate and n-butyl. A mixed solution consisting of 307 parts of methacrylate, 70 parts of glycidyl methacrylate and 18 parts of t-butylperoxy-2-ethylhexanoate (hereinafter abbreviated as TBPEH) was added dropwise over 4 hours. After completion of dropping, the mixture was reacted at 110 ° C. for 7 hours to obtain a solution of copolymer (B-1) having a nonvolatile content of 40.5% and a weight average molecular weight of 16,000.

(Synthesis Example 2)
Into the same four-necked flask as in Synthesis Example 1, 1540 parts of propylene glycol monomethyl ether acetate was charged and heated to 110 ° C. under a nitrogen stream, then 597 parts of methyl methacrylate, 261 parts of n-butyl methacrylate, 142 parts of glycidyl methacrylate. And the liquid mixture which consists of 18 parts of TBPEH was dripped over 4 hours. After completion of the dropwise addition, the mixture was reacted at 110 ° C. for 7 hours to obtain a solution of a copolymer (B-2) having a nonvolatile content of 39.8% and a weight average molecular weight of 15,000.

(Synthesis Example 3)
Into the same four-necked flask as in Synthesis Example 1, 1540 parts of propylene glycol monomethyl ether acetate was charged and heated to 110 ° C. under a nitrogen stream, and then 547 parts of methyl methacrylate, 173 parts of n-butyl methacrylate, 280 parts of glycidyl methacrylate. And the liquid mixture which consists of 18 parts of TBPEH was dripped over 4 hours. After completion of the dropwise addition, the mixture was reacted at 110 ° C. for 7 hours to obtain a solution of a copolymer (B-3) having a nonvolatile content of 40.0% and a weight average molecular weight of 16,000.

(Synthesis Example 4)
Into the same four-necked flask as in Synthesis Example 1, 1540 parts of propylene glycol monomethyl ether acetate was charged, heated to 110 ° C. under a nitrogen stream, and then mixed liquid consisting of 856 parts of benzyl methacrylate, 142 parts of glycidyl methacrylate and 18 parts of TBPEH. Was added dropwise over 4 hours. After completion of the dropwise addition, the mixture was reacted at 110 ° C. for 7 hours to obtain a polymer (B-4) solution having a nonvolatile content of 38.1% and a weight average molecular weight of 14,000.

(Synthesis Example 5)
By reacting the solid of the polymer (B-2) obtained by drying the solution of the polymer (B-2) of Synthesis Example 2 under reduced pressure (60 ° C., 10 hours) and hydrochloric acid, the polymer (B -2) A polymer (B-5) in which the epoxy group in the ring was opened to give an α-chlorohydrin was obtained.

(Synthesis Example 6)
Into the same four-necked flask as in Synthesis Example 1, 1540 parts of propylene glycol monomethyl ether acetate was charged and heated to 110 ° C. under a nitrogen stream, and then composed of 597 parts of methyl methacrylate, 261 parts of n-butyl methacrylate and 18 parts of TBPEH. The mixture was added dropwise over 4 hours. After completion of the dropwise addition, the mixture was reacted at 110 ° C. for 7 hours to obtain a solution of a copolymer (B-6) having a nonvolatile content of 39.8% and a weight average molecular weight of 15,000.

  10 g of FASTOGEN GREEN A110 (poly brominated zinc phthalocyanine pigment manufactured by DIC Corporation) and 1.25 g of the copolymer (B-1) solution (solid content 40.5%) of Synthesis Example 1 together with 589 g of water, The mixture was charged into a 1 liter autoclave, heated to 130 ° C. over 1 hour with stirring, and held at that temperature for 1 hour to carry out resin treatment on the pigment surface. After allowing to cool to room temperature, suction filtration and washing with 2 liters of warm water were performed. The obtained wet cake was dried at 90 ° C. for 12 hours and pulverized in a lab mill to obtain a surface-treated organic pigment (X-1) having an average primary particle diameter of 100 nm or less.

  The copolymer (B-2) solution of Synthesis Example 2 (B-2) solution (Synthesis content 40.5%) 1.25 g of the copolymer (B-2) solution of Synthesis Example 2 (so that the amount of the nonvolatile content is the same) A surface-treated organic pigment (X-2) having an average primary particle size of 100 nm or less was obtained in the same manner as in Example 1 except that the solid content was 39.8%.

  Copolymer (B-3) solution of Synthesis Example 3 (B-3) solution (Synthesis content 40.5%) 1.25 g of copolymer (B-3) solution of Synthesis Example 3 A surface-treated organic pigment (X-3) having an average primary particle size of 100 nm or less was obtained in the same manner as in Example 1 except that the solid content was 39.8%.

(Comparative Example 1)
Hydran AP-40F (polyurethane resin aqueous dispersion manufactured by DIC Corporation) so that 1.25 g of the copolymer (B-1) solution (solid content 40.5%) of Synthesis Example 1 becomes the same amount in non-volatile content. The surface-treated organic pigment (X-4) was obtained in the same manner as in Example 1 except that (Liquid) was used.

2.48 parts of the surface-treated organic pigment (X-1) obtained in Example 1 above, 1.24 parts of BYK-LPN6919 (dispersant manufactured by Big Chemie) manufactured by BYK Chemie, Inc., UNIDIC ZL295 (acrylic resin manufactured by DIC Corporation) ) Along with 1.86 parts and propylene glycol monomethyl ether acetate 10.92 parts, 0.3 to 0.4 mm zircon beads were used for dispersion for 2 hours with a paint conditioner manufactured by Toyo Seiki Co., Ltd.
To add 4.0 parts of this colored composition (I), 2.10 parts of Unidic ZL295, and 2.00 parts of propylene glycol monomethyl ether acetate, and mix with a paint conditioner to form a green pixel part for a color filter. A composition for evaluation was obtained.
This evaluation composition was spin-coated on soda glass while changing the film thickness, and dried at 90 ° C. for 3 minutes to obtain an evaluation glass substrate. Using this glass substrate, chromaticity (x, y) in a C light source was measured with MCPD-3000 manufactured by Otsuka Electronics Co., Ltd. Moreover, the chromaticity after heating the glass substrate for evaluation at 230 degreeC for 1 hour was also measured.

  Example 4 except that the same amount of the surface-treated organic pigment (X-2) obtained in Example 2 was used instead of 2.48 parts of the surface-treated organic pigment (X-1) obtained in Example 1 above. A series of operations were performed in the same manner as described above to obtain a glass substrate for evaluation, and measurement was performed in the same manner.

  Example 4 except that the same amount of the surface-treated organic pigment (X-3) obtained in Example 3 was used instead of 2.48 parts of the surface-treated organic pigment (X-1) obtained in Example 1 above. A series of operations were performed in the same manner as described above to obtain a glass substrate for evaluation, and measurement was performed in the same manner.

(Comparative Example 2)
Example 4 except that the same amount of the surface-treated organic pigment (X-4) obtained in Comparative Example 1 was used instead of 2.48 parts of the surface-treated organic pigment (X-1) obtained in Example 1 above. A series of operations were performed in the same manner as described above to obtain a glass substrate for evaluation, and measurement was performed in the same manner.

  The evaluation results of Examples 4 to 6 and Comparative Example 2 are shown in Table 1. In the table, “after PB” means after heating at 230 ° C. for 1 hour.

As can be seen from the comparison between Example 4 and Comparative Example 1 in Table 1 above, the specific copolymer (B) used in the present invention has an initial and post-PB ratio compared with the conventionally used polyurethane resin. It is clear that the difference between the luminance value and the chromaticity value is small, and even if the thermal history is received, the fluctuation of the luminance and chromaticity is small and the heat resistance is excellent.
In each of Examples 4 to 6, both the brightness and chromaticity were improved as absolute values after PB compared to the initial stage, and the side chain epoxy group occupied in the specific copolymer (B) at the time of preparation. There was a tendency for the absolute value of the initial luminance to increase as the content ratio of increased.

A solution of 85 parts of FASTOGEN BLUE AE-8 (ε-type copper phthalocyanine pigment manufactured by DIC Corporation), 5 parts of copper phthalocyanine phthalimide methyl derivative having an average number of substituents of 1.4, and the polymer (B-2) of Synthesis Example 2 under reduced pressure 10 parts of a solid of polymer (B-2) obtained by drying (60 ° C., 10 hours), 1000 parts of crushed sodium chloride, and 160 parts of diethylene glycol were charged into a double-arm kneader, Kneaded for hours.
The obtained contents are washed with a large excess of water, filtered, and washed with water until the filtrate has a specific conductivity of (the specific conductivity of raw water + 20 μS / cm or less), whereby an ε-type copper phthalocyanine surface-treated organic pigment is obtained. Wet cake was obtained. The obtained wet cake was transferred to a beaker, 3000 parts of a 2% hydrochloric acid aqueous solution was added, dispersed by stirring to form a slurry, stirred at 70 ° C. for 1 hour, filtered and washed with water to obtain a wet cake.
The obtained wet cake was transferred to a beaker, 3000 parts of water at room temperature was added, and the mixture was stirred and dispersed to obtain a slurry. Subsequently, an aqueous sodium hydroxide solution of 5 parts of copper phthalocyanine sulfonic acid derivative having an average number of substituents of 0.8 is added to the pigment slurry, and after stirring for 1 hour, hydrochloric acid is added to return the pH of the slurry to 7, It was deposited on the surface. After being kept for 1 hour, it was filtered, washed with warm water, dried and pulverized to obtain a blue surface-treated organic pigment having an average primary particle size of 100 nm or less.

10 parts of the blue surface-treated organic pigment thus obtained are put in a polyvin, 55 parts of propylene glycol monomethyl ether acetate, 7.0 parts of BYK (trade name) LPN21116 (manufactured by Big Chemie Co., Ltd.), 0.3-0 4 mmφ Sepul beads were added and dispersed for 4 hours with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.) to obtain a pigment dispersion. 75.00 parts of this pigment dispersion, 5.50 parts of polyester acrylate resin (Aronix (trade name) M7100, manufactured by Toa Gosei Chemical Co., Ltd.), dipentaerythritol hexaacrylate (KAYARAD (trade name) DPHA, Nippon Kayaku) 5.00 parts, benzophenone (KAYACURE (trade name) BP-100, manufactured by Nippon Kayaku Co., Ltd.) 1.00 parts, Euker Ester EEP 13.5 parts with a dispersion stirrer, and pore size 1.0 μm The color resist was obtained by filtering with a filter. This color resist was applied to 50 mm × 50 mm, 1 mm thick glass using a spin coater so that the dry film thickness was 2 μm, and then pre-dried at 90 ° C. for 20 minutes to form a coating film. Subsequently, after pattern exposure with ultraviolet rays through a photomask, the unexposed portion was washed in a 0.5% aqueous sodium carbonate solution and baked at 230 ° C. for 60 minutes to obtain a color filter.

Using the color filter thus obtained, the luminance Y of the C light source was measured with an MCPD-3000 manufactured by Otsuka Electronics Co., Ltd. and found to be 13.49. The luminance of the color filter after heating for 1 hour at 230 ° C. was measured to be 13.42.

  A blue surface-treated organic pigment was obtained in the same manner as in Example 7 except that the polymer (B-5) was used instead of the polymer (B-2) in Example 7, and a color filter was obtained using it. As a result, the luminance Y after heating at 230 ° C. for 1 hour was 13.50, and the luminance after heating at 230 ° C. for 1 hour was 13.43.

(Comparative Example 3)
A blue surface-treated organic pigment was obtained in the same manner as in Example 7 except that the polymer (B-6) was used in place of the polymer (B-2) in Example 7, and a color filter was obtained using it. As a result, the luminance Y after heating at 230 ° C. for 1 hour was 13.45, and the luminance after heating at 230 ° C. for 1 hour was 13.26.

The evaluation results of Examples 7 to 8 and Comparative Example 3 are shown in Table 2.

  According to the present invention, due to the unique heat resistance due to the interaction between the organic pigment (A) and the specific copolymer (B), it is possible to provide a colored product having a small hue change even when subjected to a thermal history. When used for the preparation of the pixel portion of the filter, a liquid crystal display device capable of high-luminance and capable of liquid crystal display with excellent luminance even when subjected to a heat history for a long time can be provided.

Claims (5)

A unit containing two or more types of (meth) acrylic acid esters containing an epoxy group and / or an α-chlorohydrin group and having different number of side chain carbon atoms per 100 parts of the organic pigment (A) in terms of mass. A surface-treated organic pigment for a color filter, comprising 0.1 to 15 parts of a polymer (B) obtained by polymerizing a monomer mixture. The surface-treated organic pigment for a color filter according to claim 1, wherein the organic pigment (A) is a phthalocyanine pigment. Obtained by polymerizing a monomer mixture containing two or more types of (meth) acrylic acid esters containing epoxy groups and / or α-chlorohydrin groups and having different side chain carbon atoms in a liquid medium. The phthalocyanine pigment (A) is heated under pressure in the presence of a non-volatile content of the polymer (B), or contains an epoxy group and / or an α-chlorohydrin group and has a different number of carbon atoms in the side chain ( A solvent obtained by subjecting the organic pigment (A) to solvent salt milling in the presence of a non-volatile content of a polymer (B) obtained by polymerizing a monomer mixture containing two or more monomers of a (meth) acrylate ester. 3. The method for producing a surface-treated organic pigment for color filter according to any one of 2 above. A color filter comprising the surface-treated organic pigment for a color filter according to claim 1 in a pixel portion. A color filter comprising a surface-treated organic pigment for a color filter obtained by the production method according to claim 3 in a pixel portion.